U.S. Marines with the Combined Arms Company, Black Sea Rotational Force familiarize Bulgarian Soldiers with the M-777 Howitzer artillery cannon during Platinum Lion 16-2 at Novo Selo Training Area, Bulgaria, Jan. 7, 2016. Exercise Platinum Lion increases readiness and demonstrates our collective ability to operate as a single force committed to protecting the sovereignty of NATO allies and other European partners. (U.S. Marine Corps Photo by Cpl. Justin T. Updegraff/ Released)

U.S. Marine Lance Cpl. Gordon Kwei, anti-tank missile man with Weapons Company, Black Sea Rotational Force, fires the tube-launched, optically tracked, wire-guided anti-tank missile (TOW), while Staff Sgt. Wayne Edmiston, combat correspondent with Black Sea Rotational Force, records it during the combined anti-armor team sustainment training for Exercise Platinum Lion 15-3, July 8 at Novo Selo Training Area, Bulgaria. The Marines launched 10 TOW missiles fired from M41 Sabers mounted to the turrets of Humvees. Marines with Black Sea Rotational Force and service members from Bulgaria, Romania, the United Kingdom and Albania are conducting the two-week exercise to promote regional cooperation and foster interoperability in order to combat security threats. (U.S. Marine Corps photo by 1st Lt. Sarah E. Burns)

U.S. Marine Sgt. Steven Mashburn, a squad leader with Black Sea Rotational Force, right, holds the American flag during the opening ceremony for Exercise Saber Strike at the Pabrade Training Area, Lithuania, June 8, 2015. The exercise brings NATO and other partner nations together for a multilateral training event designed to promote regional stability and security, strengthen partnerships, and foster trust. (U.S. Marine Corps photo by Sgt. Paul Peterson/Released)